Date: Thu, 30 Nov 2006 15:28:46 -0500 (EST) From: Daniel Eischen <deischen@freebsd.org> To: Christopher Olsen <cwolsen@domainatlantic.com> Cc: freebsd-hackers@freebsd.org Subject: Re: PRINTF, STDOUT Message-ID: <Pine.GSO.4.64.0611301524520.27732@sea.ntplx.net> In-Reply-To: <200611301954.47319.cwolsen@domainatlantic.com> References: <200611301954.47319.cwolsen@domainatlantic.com>
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On Thu, 30 Nov 2006, Christopher Olsen wrote:
> Hello,
>
> I've been tracing the printf function from the FreeBSD 6.x libc... I'm trying
> to figure out what mechanism transfers the data from the processes FILE to
> the system so it's written out to the screen...
>
>> From my findings I get to a function __sfvwrite(FILE,buf) {}
>
> however this just copies into the FILE's buffer and there are no systems
> between this point and returning back from the printf call
__sfvwrite() -> __fflush() -> __sflush -> _swrite() ->
(via fp->_write) __swrite() -> _write()
Note that _write() is a weak reference to __sys_write() which
is the actual system call.
--
Dan
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